A Wealth-X report from earlier this month found that the U.S. has the largest population of ultra-high-net-worth individuals (UHNWIs) worldwide. Defined as being worth $30 million or more, the U.S. has 80,000 such individuals (31 percent of the global population), higher than Japan, China, Germany, Canada and France combined.

For example, China saw its UHNWI population grow 19 percent between 2016 and 2017, twice the growth rate of North America. Over the past five years, another and unlikely Asian nation has been leading the world in super rich population growth.

According to Wealth-X, Bangladesh saw its ultra-rich club expand by 17.3 percent between 2012 and 2017. During the same period, China's UHNWI population grew 13.4 percent while Vietnam's increased 12.7 percent. The U.S. came tenth for UHNWI population growth with 8.1 percent.